Oedichirus clavulus, Herman, 2013

Herman, Lee H., 2013, Revision Of The New World Species Of Oedichirus (Coleoptera: Staphylinidae: Paederinae: Pinophilini: Procirrina), Bulletin of the American Museum of Natural History 2013 (375), pp. 1-137 : 64-66

Oedichirus clavulus , new species

Figures 40 , 98–102

TYPE MATERIAL: Holotype. Male. ‘‘Bras.Petropolis Prov. R. Janeiro III.1850.Sahlberg/ geniculatus Sahlb. det. Bernh. minor/Chicago NHMus M.Bernhauer Collection/ Holotype Oedichirus clavulus Herman. ’’ Deposited in the Field Museum of Natural History.

PARATYPE: One male. [ Brazil:] Rio Jan °, Fry ( FMNH).

TYPE LOCALITY: Brazil: Rio de Janeiro: Petrópolis (22 ° 309S, 43 ° 089W; (coordinates from Times Books, 1999).

DIAGNOSIS: Oedichirus clavulus is one of a cluster of four species (see also O. clavolateralis , O. exilis , and O. geniculatus ) that have both a stout, curved, strongly sclerotized process extending laterally from the right apical margin of the aedeagal ventral sclerite (fig. 99) and a short, wide, asymmetrical emargination of the posterior margin of sternum VIII (fig. 102). The males of O. clavulus can be separated from the other species of this species group by the short, stout, apically blunt peg on the right lateral apical margin of the ventral sclerite of the aedeagus at the base of the apicoventral process (figs. 98, 99). Among the other species, O. geniculatus (fig. 141) has no knob, peg, spine, lobe, or swelling in the aforementioned position. Oedichirus clavolateralis has an apically blunt knob extending lateroposteriorly (figs. 89, 93) from about the same position as for O. clavulus and the left side of the anterior margin of the ventral sclerite of the former is lobed (fig. 90), and the knob is lacking in O. clavolateralis . In lateral view the knob extending from the lateral dorsal region of the apicoventral process of O. exilis (fig. 129) is wider basally and more strongly tapered and the gap between the knob and the base of the apicoventral process wider than for O. clavulus (fig. 98), whose knob is more gradually tapered and the gap between the knob and the base of the apicoventral process is narrower.

Oedichirus clavulus is one of eight New World species with bicolored legs and a median point extending from the transverse basal ridge of tergum VIII. Also included among these species are O. brunneus , O. bullaglaber , O. bullahirtus , O. clavolateralis , O. exilis , O. geniculatus , and O. sparsipennis . Tergum III of both O. bullaglaber and O. bullahirtus has a median point (as for sternum VIII, fig. 73) that O. clavulus lacks. Characters that separate males of O. clavolateralis , O. exilis , and O. geniculatus from O. clavulus are presented in the preceding paragraph and only O. brunneus and O. sparsipennis remain; both are known only by females. The lateroapical process of IX for O. clavulus (LLaP/L9 5 2.3– 2.4) is more than twice as long as the midbasal length of tergum IX, but for the two remaining species the process is twice as long as the midbasal length for O. brunneus (LLaP/ L9 5 2.0), and about a third shorter than the midbasal length of tergum IX for O. sparsipennis (LLaP/L9 5 1.7).

DESCRIPTION: Length: 7.0– 7.7 mm. Length of head: 0.8 mm. Width of head: 1.1 mm. Pronotal length: 1.3 mm. Pronotal width: 1.0 mm. Elytral length: 1.0 mm. Elytral width: 1.1 mm.

Body concolorous dark reddish brown to nearly black, elytra paler and more notably reddish brown, particularly posteriorly and laterally. Legs bicolored, yellowish brown with femorotibial spot dark reddish brown; tibial spot smaller, paler, less demarcated.

Head wider than long (HW/HL: 1.4). Frontoclypeal ridge incomplete, separated medially. Dorsal surface without V-shaped depression; surface with dense, coarse punctation anteriorly, medially, and laterally, but less dense midbasally. Labrum quadridentate; surface without tubercle near submedial denticle.

Pronotum about one fifth longer than wide (PL/PW: 1.2). Pronotum polished, with coarse, moderately dense punctation anteriorly and sparser laterally; surface with coarsely punctate, moderately deep, submedial groove on basal two thirds. Elytra about a tenth wider than long (EW/EL: 1.1); surface flat to slightly convex and coarsely punctate.

Abdomen densely and irregularly punctate and without transverse rows of punctures. Segment III without paratergite; paratergal carina present and extending to near middle of segment, but less strongly developed beyond spiracle. Tergum III without median point extending from transverse basal ridge. Tergum VIII with apically, narrowly open median point extending from transverse basal ridge; posterior margin feebly rounded to weakly emarginate. Tergum IX with lateroapical process more than twice as long as midbasal length (LLaP/L9 5 2.3–2.4), slightly bent ventrally, and approximately parallel to other process; ventromedial margin without posteriorly directed spur (cf. fig. 158).

MALE: Sternum VI unmodified. Sternum VII with small, impunctate, asetate, median spot near posterior margin. Sternum VIII with wide, deep, asymmetrical emargination of posterior margin (fig. 102); emargination about one sixth of length of sternum, wider than deep, and mostly to left of midlongitudinal line; right margin of emargination shorter and more steeply sloped than left; emargination moderately broadly rounded basally and submarginal edge translucent; surface with slight carina laterad of left margin of emargination and with cluster of short, spinelike setae laterad of both sides of emargination near posterior margin; surface without without comb or depression; transverse basal ridge unevenly sinuate and without median point. Tergum IX with anteroventral angle extended anteriorly as moderately large process. Sternum IX (fig. 101) slightly asymmetrical; anterior margin narrow and strongly rounded; posterior margin wide and broadly rounded; right lateral margin broadly rounded left margin slightly and broadly sinuate.

Aedeagus asymmetrical (figs. 98–100). Ventral sclerite with apical margin weakly sinuate (fig. 99), with large, thick, curved, strongly sclerotized apicoventral process extending from right apicolateral margin (figs. 98, 99); apicoventral process wide in lateral view and extending lateroventrally with apical portion bent dorsoanteriorly (figs. 98, 99); ventral sclerite with apically rounded, cylindriform peg arising from right dorsolateral margin at base of apicoventral process (fig. 98). Parameres moderately broad, flattened, tapered apically, and fused to median lobe for most of length, free of median lobe near apex; parameres of more or less equal length.

FEMALE: Unknown.

MALE/FEMALE ASSOCIATION: The type locality for O. clavulus , a species of the geniculatus complex, is Petropolis from which only one male is known. A paratype male of O. clavulus was collected from ‘‘Rio Jan ° ’’ by (A.) ‘‘Fry’’ and is possibly from the city of Rio de Janeiro. The handwritten label is unique and seven other specimens, all females, have that label. However, although they share a characteristic label, the collecting dates and site(s) are unknown, so it is uncertain that they were collected at the same time and place. The genital segments of six of the seven specimens were removed for examination. Five specimens are O. geniculatus . The sixth female is a different species; unlike O. geniculatus and others of the species complex, its tergum III has a basal median point (as for sternum VIII, fig. 73), which is lacking in all the species of the complex and has not been found on any males from Rio de Janeiro. Only three species with a median point of tergum III are known, one each in Santa Catarina , Paraná, and São Paulo states. The sixth specimen lacked an abdomen.

ETYMOLOGY: The name is from the Latin clavus, ‘‘nail,’’ and refers to the small, posteriorly directed peg on the right lateroapical margin of the aedeagal ventral sclerite.

DISTRIBUTION: Known only from the state of Rio de Janeiro, Brazil (fig. 40).

REMARKS: Oedichirus clavolateralis , O. clavulus , O. exilis , and O. geniculatus are the only species reported from the state of Rio de Janeiro. One of the two males of O. clavulus was collected at Petropolis by Sahlberg and identified by Bernhauer as O. geniculatus . Sahlberg made two trips to Brazil. During his second trip he was in Petropolis from December 1849 to May 1850, and then again in December 1850; it was on the first part of that second trip that he collected the holotype of O. clavulus in March (Rinne, e-mail, April 2, 2009). Based on the material I have seen and on the lack of contradictory published information, the holotype of O. clavulus is the second specimen of the genus collected in the New World.

The paratype was collected from ‘‘Rio Jan ° ’’ by Alexander Fry, but it is unclear whether the locality refers to the state or the city. Fry lived in Rio de Janeiro from 1838 to 1854 ( Anonymous, 1905: 119), but certainly may have traveled outside the city to collect in other locales of the state.

Figures

Figs. 39–40. Oedichirus species. Distribution. 39. Mesoamerica and the Caribbean. 40. South America. (Species described prior to present work preceded with *. Symbols ³ or ♀ signify species known only by the sex indicated. Open circle denotes multiple collecting sites.)

Figs. 98–102. Oedichirus clavulus. 98. Aedeagus, right lateral. 99. Aedeagus, ventral. 100. Aedeagus, left lateral. 101. Sternum IX, male. 102. Sternum VIII, male.